Fish Assemblage Response to a Small Dam Removal in the Eightmile River System,Connecticut, USA

We examined the effects of the Zemko Dam removal on the Eightmile River system in Salem, Connecticut, USA. The objective of this research was to quantify spatiotemporal variation in fish community composition in response to small dam removal. We sampled fish abundance over a 6-year period (2005–2010) to quantify changes in fish assemblages prior to dam removal, during drawdown, and for three years following dam removal. Fish population dynamics were examined above the dam, below the dam, and at two reference sites by indicator species analysis, mixed models, non-metric multidimensional scaling, and analysis of similarity. We observed significant shifts in fish relative abundance over time in response to dam removal. Changes in fish species composition were variable, and they occurred within 1 year of drawdown. A complete shift from lentic to lotic fishes failed to occur within 3 years after the dam was removed. However, we did observe increases in fluvial and transition (i.e., pool head, pool tail, or run) specialist fishes both upstream and downstream from the former dam site. Our results demonstrate the importance of dam removal for restoring river connectivity for fish movement. While the long-term effects of dam removal remain uncertain, we conclude that dam removals can have positive benefits on fish assemblages by enhancing river connectivity and fluvial habitat availability.     

Thermal reaction norms for growth vary among cohorts of Pacific cod (Gadus macrocephalus)

While much effort has been directed at determining the spatial scales of adaptation in thermal reaction norms for growth, it is widely assumed that these reaction norms have high temporal stability. Water temperatures in the Gulf of Alaska in 2007 were the coldest on record since the mid-1970s and we present evidence that the thermal reaction norm for growth of age-0 Pacific cod (Gadus macrocephalus) in this cohort differed significantly from two adjacent cohorts. In addition to exhibiting higher growth potential at low temperatures, the 2007 cohort had a higher mean vertebral count, consistent with the widespread thermal effect known as “Jordan’s Rule.” Variation among cohorts in these physiological and morphological traits suggests a persistent response to environmental history (epigenetic effect). Temperature-induced phenotypic plasticity in the reaction norm for growth has significant implications for using growth rates to evaluate habitat quality and illustrates the complex responses of fishes to climate variability.     

Does carbon limitation reduce nitrogen retention in soil?

Environmental Chemistry Letters - Artificial soils made from waste materials offer an alternative to imported natural topsoils, notably in large-scale groundwork and reclamation projects. Benefits...     

The potential for combining indigenous and western knowledge in reducing vulnerability to environmental hazards in small island developing states

The benefits of indigenous knowledge within disaster risk reduction are gradually being acknowledged and identified. However, despite this acknowledgement there continues to be a gap in reaching the right people with the correct strategies for disaster risk reduction.

This paper identifies the need for a specific framework identifying how indigenous and western knowledge may be combined to mitigate against the intrinsic effects of environmental processes and therefore reduce the vulnerability of rural indigenous communities in small island developing states (SIDS) to environmental hazards. This involves a review of the impacts of environmental processes and their intrinsic effects upon rural indigenous communities in SIDS and how indigenous knowledge has contributed to their coping capacity. The paper concludes that the vulnerability of indigenous communities in SIDS to environmental hazards can only be addressed through the utilisation of both indigenous and Western knowledge in a culturally compatible and sustainable manner.     

Strengthening the employment relationship: The effects of work‐hours fit on key employee attitudes

Today's hourly workers are facing revised work schedules and shifting hours, which may have critical implications for employment relationships. This study considers the impact of work‐hours fit on key attitudes of hourly employees—perceived organizational support, job stress, work–family conflict, intent to turnover, and life satisfaction. We define work‐hours fit as the difference between an employee's desired number of hours and the actual hours worked, and we examine both the congruence of work‐hours fit and the degree of misfit. We also examine the moderating impact of the type of misfit, defined as working too many versus too few hours. Results indicate that, in our sample, hourly employees are typically not working the hours they prefer. As predicted, work‐hours fit impacts the attitudes we examined, and, when considering the type of misfit, congruence matters more for life satisfaction and intent to turnover. Results also indicate working too few hours impacts job stress and life satisfaction, whereas working too many effects work–family conflict. This paper demonstrates the importance of preferences, as a reflection of time/money resource trade‐offs, and offers ways for employers to improve work–family facilitation and strengthen their employment relationships. Copyright © 2014 John Wiley & Sons, Ltd.     

Impact of methylene chloride on microorganisms and phenanthrene mineralization in soil

This study investigated the effects of the quantity of methylene chloride, used as a carrier solvent for phenanthrene when added to soil, on phenanthrene mineralization kinetics, soil phospholipid fatty add profiles (PLFA), and phenanthrene distribution. Methylene chloride dosages of 25 microL/g soil or more resulted in an enrichment of saturated PLFAs, suggesting soil microorganisms had adjusted their cell membranes in response to the solvent. A greater fraction of phenanthrene mineralized when spiked in 5 microL/g than in 25 microL/g methylene chloride suggesting that the methylene chloride became toxic to phenanthrene-degrading organisms in soil. Phenanthrene was more equally distributed among 0.1 g soil subsamples if spiked in 25 than 5 or 1 microL methylene chloride per gram soil. Thus the amount of methylene chloride used to spike phenanthrene in soil strongly impacted the mineralization kinetics, phenanthrene distribution, and microbial community in soil. Because a variety of spiking methods are used in biodegradation research, scientists should consider the quantity of solvents used when comparing results among different studies.     

Environmental inequality and flood hazard

This paper reports findings from research conducted for the Environment Agency1 investigating the social distribution of the risk of flooding in England and Wales. Following a broadly outcome based analysis, and using socio-geographic modelling techniques and the 1991 Census, the social class characteristics of the population at risk from flooding were explored and compared with the population considered not at risk as a means to uncover any evidence of social inequality. The Environment Agency indicative flood plain maps (1 in 100 year return for fluvial and 1 in a 200 year return for tidal flooding) were used to identify at risk areas. Two different methods of capturing the at risk population were employed; one based on census enumeration districts and the other using surface population models which redistribute the area population over a grid surface of the area of interest. The two methods provide completely different results. The enumeration district method indicates that those in higher social classes are the most likely to be exposed to flood hazard while the grid method indicates that it is those in the lower social classes who are most at risk. We suggest that the grid method provides a more accurate analysis but highlight the significant effect that the choice of areal unit and spatial analysis can have on conclusions about the extent of any inequality in vulnerability to flooding.     

Developing the ethical matrix as a decision support framework: GM fish as a case study

The Ethical Matrix was developed to help decision-makers explore the ethical issues raised by agri-food biotechnologies. Over the decade since its inception the Ethical Matrix has been used by a number of organizations and the philosophical basis of the framework has been discussed and analyzed extensively. The role of tools such as the Ethical Matrix in public policy decision-making has received increasing attention. In order to further develop the methodological aspects of the Ethical Matrix method, work was carried out to study the potential role of the Ethical Matrix as a decision support framework. When considering which frameworks to apply when analyzing the ethical dimensions of the application of agri-food biotechnologies, it is important to clarify the substantive nature of any prospective framework. In order to further investigate this issue, reflections on the neologism “ethical soundness” of an ethical framework are presented here. This concept is introduced in order to provide more structured evaluations of a range of ethical tools, including ethical frameworks such as the Ethical Matrix. As well as examining the philosophical dimensions of the method, theoretical analysis and literature studies were combined with stakeholder engagement exercises and consultations in order to review the Ethical Matrix from a user perspective. This work resulted in the development of an Ethical Matrix Manual, which is intended to act as a guide for potential user groups.